China's deep-sea manned submersible Jiaolong, is seen on this photo taken on April 22, 2017. [Photo/Xinhua]

Jiaolong, China's manned submersible, went through a dive simulation in Sanya, Hainan Province on Saturday to prepare for a deep descent in the South China Sea.

The submersible stayed underwater for 18 minutes in Saturday's drill before returning Xiangyanghong 09, the mother ship, completing tasks including underwater training for its crew.

Zhang Weijia, who participated, said she was very excited entering the submersible for the first time to learn about its facilities, practical operation and emergency escape.

Jiaolong's South China Sea dive is part of the second stage of China's 38th ocean scientific expedition. The expedition will last for about four months.

The drill was necessary for testing equipment and personnel, said Wu Changbin, general commander of the second stage of the expedition. Currently the Jiaolong's "technological status" is stable and the cooperation among various departments is smooth, Wu said.

Jiaolong completed a deep-sea operation in the northwestern Indian Ocean earlier this year in the mission's first stage. It will also conduct surveys in the Yap Trench and the Mariana Trench in the third stage.

Named after a mythical dragon, Jiaolong reached its deepest depth of 7,062 meters in the Mariana Trench in June 2012. (Xinhua)